Adhesive composition for semiconductor, adhesive film for semiconductor, and dicing die bonding film

ABSTRACT

The present invention relates to an adhesive composition for a semiconductor including: a thermoplastic resin having a glass transition temperature of −10° C. to 20° C.; a curing agent containing a phenol resin having a softening point of 70° C. or more; a solid epoxy resin; and a liquid epoxy resin, wherein a weight ratio of the total contents of the solid epoxy resin and the liquid epoxy resin to the thermoplastic resin is 1.6 to 2.6, an adhesive film for a semiconductor including the adhesive composition for a semiconductor, a dicing die bonding film including an adhesive layer including the adhesive composition for a semiconductor, and a method for dicing a semiconductor wafer using the dicing die bonding film.

TECHNICAL FIELD Cross-Reference to Related Application(s)

This application claims the benefit of Korean Patent Application No.10-2015-0060690 filed on Apr. 29, 2015 with the Korean IntellectualProperty Office, the disclosure of which is incorporated herein byreference in its entirety.

The present invention relates to an adhesive composition for asemiconductor, an adhesive film for a semiconductor, and a dicing diebonding film, and more specifically to an adhesive composition for asemiconductor, an adhesive film for a semiconductor, and a dicing diebonding film that have low viscosity, and yet have high elasticity,excellent mechanical properties, and high adhesive strength.

BACKGROUND OF ART

Recently, with an increasing tendency of electronic devices towardminiaturization, high performance, and large capacity, a demand for highdensity and highly integrated semiconductor packages has been rapidlyincreasing, and thus the size of semiconductor chips increasinglybecomes large, and in order to improve the degree of integration, astack package method of stacking chips in multistages is beingincreasingly used.

In such a multistage stack structure, in order to secure a space inwhich a lower bonding wire that electrically connects a lower chip and asubstrate is positioned, a spacer is introduced at the interface betweenthe lower chip and the upper chip. In case such a spacer for securing aspace is introduced, the total thickness of the package becomes thickand a separate process of attaching the spacer is added.

In order to overcome the problem, recently, a method of fillingunevenness such from as a wire and the like using an adhesive having lowviscosity at a high temperature is used instead of the spacer. However,there was a limit in that the adhesive having low viscosity may notsecure high elasticity and has high elongation at break. Further, if theelasticity of the adhesive itself decreases, due to heat generated whena wafer is cut, the adhesive may be softened to partially generate aburr, and thus it may contaminate the wafer, or may be used by beingmixed with an adhesive of the lower support film, thus loweringsubsequent pick-up efficiency.

In addition, recently, as a semiconductor chip has become thinner, thereis a problem in that the chip is damaged in the existing blade cuttingprocess thus lowering a yield, and in order to overcome this, apreparation process of firstly cutting a semiconductor chip with a bladeand then polishing has been suggested. An adhesive should be able to becut through an expanding process at a low temperature so as to beapplied for such a preparation process. However, an adhesive having lowductility is not easily cut at room temperature, and when allowed tostand at room temperature after being cut, re-adhesion occurs due to thelow ductility, consequently lowering the production yield ofsemiconductor chips.

DETAILED DESCRIPTION OF THE INVENTION Technical Problem

It is an object of the invention to provide an adhesive composition fora semiconductor that has low viscosity, and yet has high elasticity,excellent mechanical properties, and high adhesive strength.

It is another object of the invention to provide an adhesive film for asemiconductor that has low viscosity, and yet has high elasticity,excellent mechanical properties, and high adhesive strength.

It is still another object of the invention to provide a dicing diebonding film that has low viscosity, and yet has high elasticity,excellent mechanical properties, and high adhesive strength, and thusmay prevent burr generation and realize high pick-up efficiency.

It is still another object of the invention to provide a method fordicing a semiconductor wafer using the dicing die bonding film.

Technical Solution

Provided herein is an adhesive composition for a semiconductor includinga thermoplastic resin having a glass transition temperature of −10° C.to 20° C.; a curing agent containing a phenol resin having a softeningpoint of 70° C. or more; a solid epoxy resin; and a liquid epoxy resin,wherein a weight ratio of the total contents of the solid epoxy resinand the liquid epoxy resin to the thermoplastic resin is 1.6 to 2.6.

In the adhesive composition for a semiconductor, the weight ratio of thetotal contents of the solid epoxy resin and the liquid epoxy resin tothe thermoplastic resin may be 1.7 to 2.5.

In the adhesive composition for a semiconductor, the weight ratio of thephenol resin to the total weight of the thermoplastic resin, the phenolresin, and the liquid epoxy resin may be 0.280 or more, or 0.300 to0.600.

The liquid epoxy resin may have a viscosity of 500 mPa·s to 20,000 mPa·sat 25° C.

The liquid epoxy resin may have an epoxy equivalent weight of 100 to1,000.

The phenol resin may have a hydroxyl equivalent weight of 80 g/eq to 400g/eq and a softening point of 70° C. to 160° C.

The phenol resin may have a hydroxyl equivalent weight of 100 g/eq to178 g/eq.

The phenol resin may have a softening point of greater than 100° C. and160° C. or less, or 105° C. to 150° C.

The weight ratio of the liquid epoxy resin to the phenol resin may be0.5 to 1.5.

The solid epoxy resin may include one or more kinds of resins selectedfrom the group consisting of a biphenyl-based epoxy resin, a bisphenol Aepoxy resin, a bisphenol F epoxy resin, a cresol novolac epoxy resin, aphenol novolac epoxy resin, a tetrafunctional epoxy resin, atriphenolmethane type of epoxy resin, an alkyl modified triphenolmethanetype of epoxy resin, a naphthalene type of epoxy resin, adicyclopentadiene type of epoxy resin, and a dicyclopentadiene modifiedphenol type of epoxy resin.

The solid epoxy resin may have an average epoxy weight equivalent of 100to 1,000.

The solid epoxy resin may have a softening point of 50° C. to 120° C.

The thermoplastic resin may include one or more kinds of polymers resinselected from the group consisting of polyimide, polyether imide,polyester imide, polyamide, polyether sulfone, polyether ketone,polyolefin, polyvinylchloride, phenoxy, reactive butadiene acrylonitrilecopolymer rubber, and (meth)acrylate-based resin.

The (meth)acrylate-based resin may be a (meth)acrylate-based resinincluding a (meth)acrylate-based repeat unit containing an epoxy-basedfunctional group, and having a glass transition temperature of −10° C.to 20° C.

The (meth)acrylate-based resin may include 0.1 wt % to 10 wt % of(meth)acrylate-based repeat units containing an epoxy-based functionalgroup.

The curing agent may further include one or more kinds of compoundsselected from the group consisting of an amine-based curing agent and anacid anhydride-based curing agent.

The adhesive composition for a semiconductor may further include an ionscavenger including a metal oxide including one or more metals selectedfrom the group consisting of zirconium, antimony, bismuth, magnesium,and aluminum; porous silicate; porous alumino silicate; or zeolite.

The adhesive composition for a semiconductor may further include one ormore kinds of a curing catalyst selected from the group consisting of aphosphorous compound, a phosphorous-boron compound, and animidazole-based compound.

The adhesive composition for a semiconductor may further include one ormore kinds of additives selected from the group consisting of a couplingagent and an inorganic filler.

The adhesive composition for a semiconductor may further include 10 to90 wt % of an organic solvent.

Also, provided herein is an adhesive film for a semiconductor includingthe above-explained adhesive composition for a semiconductor.

The adhesive film may have a thickness of 1 μm to 300 μm. Further, theadhesive film may have a thickness of 1 μm or more, 3 μm or more, 5 μmor more, or 10 μm or more. In addition, the adhesive film may have athickness of 300 μm or less, 100 μm or less, 90 μm or less, or 70 μm orless.

The adhesive film for a semiconductor may include: a continuous phasebase including a thermoplastic resin having a glass transitiontemperature of −10° C. to 20° C., a curing agent containing a phenolresin having a softening point of 70° C. or more, and a liquid epoxyresin; and a solid epoxy resin dispersed in the continuous phase base.

The weight ratio of the total contents of the solid epoxy resin and theliquid epoxy resin to the thermoplastic resin may be 1.6 to 2.6, 1.7 to2.5, 1.75 to 2.4, or 1.8 to 2.3.

In the continuous phase base, the weight ratio of the phenol resin tothe total weight of the thermoplastic resin, the phenol resin, and theliquid epoxy resin may be 0.280 or more, or 0.300 to 0.600.

Further, the adhesive film for a semiconductor may be a die bondingfilm. Thus, the adhesive film for a semiconductor may include: anadhesive layer including a continuous phase base including athermoplastic resin having a glass transition temperature of −10° C. to20° C., a curing agent containing a phenol resin having a softeningpoint of 70° C. or more, and a liquid epoxy resin; and a solid epoxyresin dispersed in the continuous phase base and a release film formedon one side of the adhesive layer.

A modulus generated at 5% to 10% elongation of the adhesive film for asemiconductor at room temperature may be 50 MPa or more.

Further, elongation of the adhesive film for a semiconductor at roomtemperature may be 500% or less.

In addition, the adhesive film for a semiconductor may have a meltviscosity of 1,000 Pa·s to 4,000 Pa·s at a temperature of 110° C. and ashear rate of 5 rad/s.

The die bonding film may further include an inorganic filler dispersedin the continuous phase base.

Also provided herein is a dicing die bonding film including a baselayer; a tacky layer formed on the base film; and an adhesive layerincluding the adhesive composition for a semiconductor, formed on thetacky layer.

A modulus generated at 5% to 10% elongation of the adhesive layer atroom temperature may be 50 MPa or more.

Further, elongation of the adhesive layer at room temperature may be500% or less.

The base film has a thickness of 10 μm to 200 μm, the tacky layer has athickness of 1 μm to 600 μm, 3 μm to 500 μm, or 5 μm to 300 μm, and theadhesive film has a thickness of 1 μm to 300 μm. Further, the adhesivefilm may have a thickness of 1 μm or more, 3 μm or more, 5 μm or more,or 10 μm or more. In addition, the adhesive film may have a thickness of300 μm or less, 100 μm or less, 90 μm or less, or 70 μm or less.

Also provided herein is a method for dicing a semiconductor wafer,including the steps of: partially pre-treating a semiconductor waferincluding the dicing die bonding film; laminating a wafer on at leastone side of the dicing die bonding film so as to be completely cut orcuttable; and irradiating UV to the base film of the pre-treatedsemiconductor wafer and picking up individual chips separated by thecutting of the semiconductor.

Advantageous Effects

According to the present invention, provided are an adhesive compositionfor a semiconductor and an adhesive film for a semiconductor that havelow viscosity and yet have high elasticity, excellent mechanicalproperties, and high adhesive strength, a dicing die bonding film thathas low viscosity and yet has high elasticity, excellent mechanicalproperties, and high adhesive strength, and that may prevent burrgeneration and realize high pick-up efficiency, and a method for dicinga semiconductor wafer using the dicing die bonding film.

The adhesive composition for a semiconductor and the adhesive film for asemiconductor have low viscosity and yet have high breaking strength andlow elongation at break, and thus can be applied for non-contact typeadhesive cutting, for example, DBG (Dicing Before Grinding), as well aswafer cutting using a knife blade, and have excellent cuttability evenat a low temperature, and thus, even if allowed to stand at roomtemperature, a possibility of readhesion becomes low, thus increasingreliability and efficiency in a semiconductor manufacturing process.

Further, the adhesive composition for a semiconductor or adhesive or anadhesive film prepared therefrom may secure improved elasticity and highmechanical properties, thus preventing burr generation in a dicing diebonding film including the same and in a method for dicing asemiconductor wafer using the dicing die bonding film, furtherincreasing pick-up efficiency in a dicing process, and securing highcuttability at low and high temperatures.

DETAILED DESCRIPTION OF THE EMBODIMENTS

An adhesive composition for a semiconductor, a die bonding film, adicing die bonding film, and a method for dicing a semiconductor waferaccording to specific embodiments of the invention will now be explainedin detail.

According to one embodiment of the invention, provided is an adhesivecomposition for a semiconductor including: a thermoplastic resin havinga glass transition temperature of −10° C. to 20° C.; a curing agentcontaining a phenol resin having a softening point of 70° C. or more; asolid epoxy resin; and a liquid epoxy resin, wherein a weight ratio ofthe total contents of the solid epoxy resin and the liquid epoxy resinto the thermoplastic resin is 1.6 to 2.6.

The inventors progressed studies on the components that can be used foradhesion or packaging of semiconductor devices, confirmed throughexperiments that an adhesive or an adhesive film prepared using theadhesive composition for a semiconductor of the above embodiment may beapplied to a package of a multistage stack structure of a semiconductorchip to realize a more stable structure and excellent mechanicalproperties such as heat resistance, impact resistance, and the like, andprevent reflow cracks and the like, and particularly, even if exposed toa high temperature condition that is applied in a semiconductormanufacturing process for a long time, a void may not be substantiallygenerated, and completed the invention.

It was also confirmed through experiments that an adhesive film preparedfrom the adhesive composition for a semiconductor of the aboveembodiment has low viscosity and yet has high breaking strength and lowelongation at break, and thus can be applied for non-contact typeadhesive cutting, for example, DBG (Dicing Before Grinding), as well aswafer cutting using a knife blade, and has excellent cuttability even ata low temperature, and thus even if it is allowed to stand at roomtemperature, a possibility of readhesion becomes low, thus increasingreliability and efficiency in a semiconductor manufacturing process, andcompleted the invention.

In the adhesive composition for a semiconductor, the weight ratio of thetotal content of the solid epoxy resin and the liquid epoxy resin to thethermoplastic resin may be 1.6 to 2.6, 1.7 to 2.5, 1.75 to 2.4, or 1.8to 2.3.

As the adhesive composition for a semiconductor includes theabove-explained range of the solid epoxy resin and the liquid epoxyresin compared to the thermoplastic resin, the adhesive film preparedfrom the adhesive composition for a semiconductor may have low viscosityat a high temperature, and yet realize high elasticity, excellentmechanical properties, and high adhesive strength.

If the weight ratio of the total contents of the solid epoxy resin andthe liquid epoxy resin to the thermoplastic resin is lower than theabove-explained range, the adhesive film prepared from the adhesivecomposition for a semiconductor may exhibit high viscosity at a hightemperature or exhibit low breaking strength and high elongation atbreak, and a high temperature shearing force may also be lowered, andthus cuttability may not be sufficiently secured.

Further, if the weight ratio of the total contents of the solid epoxyresin and the liquid epoxy resin to the thermoplastic resin is greaterthan 2.6, a modulus generated at 5% to 10% elongation of the adhesivefilm prepared from the adhesive composition for a semiconductor at roomtemperature may become significantly high, or elongation of the adhesivefilm at room temperature may be significantly lowered, thus largelyinhibiting workability. Further, if the weight ratio of the totalcontents of the solid epoxy resin and the liquid epoxy resin to thethermoplastic resin is greater than 2.6, in the dicing die bonding filmmanufactured using the adhesive film prepared therefrom, a viscosityincrease rate may be significantly increased in the curing process, andthus it may be difficult to remove a void inside the film, which mayimpede reliability of a semiconductor package.

Meanwhile, the epoxy resin may form a base (or matrix) of the adhesivecomponent together with the thermoplastic resin having a glasstransition temperature of −10° C. to 20° C. and a curing agentcontaining a phenol resin having a softening point of 70° C. or more,and it allows the adhesive composition for a semiconductor or adhesiveor an adhesive film prepared therefrom to have low viscosity and yethave high breaking strength and low elongation at break.

The phenol resin may form a base (or matrix) of the adhesive componenttogether with the liquid epoxy resin and the thermoplastic resin havinga glass transition temperature of −10° C. to 20° C., wherein the phenolresin is preferably included in a content above a certain level in thebase of the adhesive component. Specifically, the weight ratio of thephenol resin to the total weight of the thermoplastic resin, the phenolresin, and the liquid epoxy resin may be 0.280 or more, 0.300 or more,or 0.300 to 0.600.

If the weight ratio of the phenol resin to the total weight of thethermoplastic resin, the phenol resin, and the liquid epoxy resin isless than 0.280 in the adhesive composition for a semiconductor, asufficient curing degree may not be afforded to the adhesive film for asemiconductor, thus lowering heat resistance, a modulus generated at 5%to 10% elongation of the adhesive film prepared from the adhesivecomposition for a semiconductor at room temperature may be significantlylowered, and elongation of the adhesive film at room temperature may besignificantly increased. Further, in a dicing die bonding filmmanufactured using the adhesive film, burrs may be excessively generatedthrough a dicing process, and a high temperature shearing force may alsobe decreased, and thus cuttability may not be sufficiently secured.

The liquid epoxy resin may form a base (or matrix) of the adhesivecomponent together with the thermoplastic resin having a glasstransition temperature of −10° C. to 20° C. and the curing agentcontaining a phenol resin, and allows the adhesive film to haverelatively low viscosity and yet have excellent adhesive strength andflow properties optimized for a semiconductor, and thus may be favorablefor void removal at the interface of initial stage curing and in a dieattachment process.

Specific kinds and properties of the liquid epoxy resin are notsignificantly limited, but for example, the liquid epoxy resin may havea viscosity of 500 mPa·s to 20,000 mPa·s at 25° C. Further, the liquidepoxy resin may have an epoxy equivalent weight of 100 to 1,000.

In the adhesive composition for a semiconductor of the above embodiment,the weight ratio of the liquid epoxy resin to the phenol resin may be0.5 to 1.5.

If the weight ratio of the liquid epoxy resin to the phenol resin is toohigh, breaking strength of the adhesive composition for a semiconductoror adhesive or an adhesive film prepared therefrom may be significantlyincreased, tensile modulus at room temperature may be lowered, andcuttability or efficiency may be lowered in a low temperature cuttingprocess.

Further, if the weight ratio of the liquid epoxy resin to the phenolresin is too low, a modulus generated at elongation at room temperaturemay become too high, or elongation at room temperature may besignificantly lowered, thus significantly lowering the yield of thefinal product, and the adhesive composition for a semiconductor or anadhesive or an adhesive film prepared therefrom may not have sufficientadhesion to a wafer, thus generating debonding between a wafer and anadhesive film in a manufacturing process.

Specific kinds and properties of the liquid epoxy resin are notsignificantly limited, but for example, the liquid epoxy resin may havea viscosity of 500 mPa·s to 20,000 mPa·s at 25° C. Further, the liquidepoxy resin may have an epoxy equivalent weight of 100 to 1,000.

Meanwhile, the curing agent included in the adhesive composition for asemiconductor may include phenol resin having a softening point of 70°C. or more. The phenol resin may have a softening point of 70° C. ormore, 80° C. or more, 70° C. to 160° C., greater than 100° C. and 160°C. or less, or 105° C. to 150° C.

The adhesive composition for a semiconductor of the above embodiment mayinclude phenol resin having a relatively high softening point, and thephenol resin having a softening point of 70° C. or more, 80° C. or more,70° C. to 160° C. or greater than 100° C. and 160° C. or less, or 105°C. to 150° C. may form a base (or matrix) of the adhesive componenttogether with the liquid epoxy resin and the thermoplastic resin havinga glass transition temperature of −10° C. to 20° C., and affords ahigher tensile modulus and excellent adhesive strength at roomtemperature and flow properties optimized for a semiconductor to theadhesive film prepared from the adhesive composition for a semiconductorof the above embodiment.

To the contrary, if the softening point of the phenol resin is less thanthe above-explained range, the tensile modulus of the adhesive filmprepared from the adhesive composition for a semiconductor of the aboveembodiment at room temperature may be lowered or elongation at roomtemperature may be significantly increased, and the melt viscosity ofthe adhesive film may be decreased or the modulus may be lowered, andthus more burrs may be generated by heat generated in a dicing processor cuttability or pick-up efficiency may be lowered. Further, if aprocess of bonding the adhesive film or the adhesive film is exposed toa high temperature condition for a long time, a lot of bleed-out may begenerated.

In addition, the phenol resin may have a hydroxyl equivalent weight of80 g/eq to 400 g/eq, 90 g/eq to 250 g/eq, 100 g/eq to 178 g/eq, or 210to 240 g/eq. As the phenol resin has the above-explained hydroxylequivalent weight range, a curing degree may be increased even with ashort curing time, thus affording a higher tensile modulus and excellentadhesive strength at room temperature to the adhesive film prepared fromthe adhesive composition for a semiconductor of the above embodiment.

In order to control the curing degree of the adhesive composition for asemiconductor or increase adhesion performance and the like, theadhesive composition may include a solid epoxy resin.

Specific examples of the solid epoxy resin may include one or more kindsof polymer resins selected from the group consisting of a biphenyl-basedepoxy resin, a bisphenol A epoxy resin, a bisphenol F epoxy resin, acresol novolac epoxy resin, a phenol novolac epoxy resin, atetrafunctional epoxy resin, a triphenolmethane type of epoxy resin, analkyl modified triphenolmethane type of epoxy resin, a naphthalene typeof epoxy resin, a dicyclopentadiene type of epoxy resin, and adicyclopentadiene modified phenol type of epoxy resin.

The solid epoxy resin may have a softening point of 50° C. to 120° C. Ifthe softening point of the solid epoxy resin is too low, adhesivestrength of the adhesive composition for a semiconductor may increase todecrease pick-up of chips after dicing, and if the softening point ofthe solid epoxy resin is too high, flowability of the adhesivecomposition for a semiconductor may be lowered, and the adhesivestrength of the adhesive film prepared from the adhesive composition fora semiconductor may be lowered.

The solid epoxy resin may have an epoxy equivalent weight of 100 to1,000.

As explained above, the adhesive composition for a semiconductor mayinclude thermoplastic resin having a glass transition temperature of−10° C. to 20° C.

Examples of the thermoplastic resin are not specifically limited, butfor example, may include polyimide, polyether imide, polyester imide,polyamide, polyether sulfone, polyether ketone, polyolefin,polyvinylchloride, phenoxy, reactive butadiene acrylonitrile copolymerrubber, (meth)acrylate-based resin, a mixture of two or more kindsthereof, or a copolymer of two or more kinds thereof.

Specifically, the (meth)acrylate-based resin may be a(meth)acrylate-based resin including a (meth)acrylate-based repeat unitincluding an epoxy-based functional group, and having a glass transitiontemperature of −10° C. to 20° C.

By using the (meth)acrylate-based resin including a (meth)acrylate-basedrepeat unit including an epoxy-based functional group, and having aglass transition temperature of −10° C. to 20° C., the adhesivecomposition for a semiconductor of the embodiment may be used foradhesion of a semiconductor or adhesion of components included in asemiconductor, or for a semiconductor package, and in case of being usedfor multistage stacking of a ultra thin wafer, an adhesive film for asemiconductor or an adhesive film for a semiconductor package that cansecure high impact resistance and improve electrical properties aftersemiconductor manufacture may be provided.

The epoxy-based functional group may be substituted one or more at therepeat unit making up the main chain of the (meth)acrylate-based resin.

The epoxy-based functional group may include an epoxy group or aglycidyl group

A (meth)acrylate-based resin including the (meth)acrylate-based repeatunits including epoxy-based functional groups in the content of 0.1 wt %to 10 wt % may have a glass transition temperature of −10° C. to 20° C.,or −5° C. to 15° C. By using a (meth)acrylate-based resin having theabove-explained glass transition temperature, the adhesive compositionfor a semiconductor may have sufficient flowability and the finallyprepared adhesive film may secure high adhesive strength, and it is easyto prepare the adhesive composition for a semiconductor in the form of athin film and the like.

The adhesive composition for a semiconductor of the above embodiment mayinclude 10 to 1,000 parts by weight of the thermoplastic resin, and 10to 1,000 parts by weight of the solid epoxy resin, based on 100 parts byweight of the phenol resin.

If the content of the thermoplastic resin is too low, a modulus aftercuring of the resin composition may rapidly increase, and thus it isdifficult to expect a stress relaxation effect between a substrate and awafer. Further, if the content of the thermoplastic resin is too high,viscosity of the composition at a B-stage may increase, and thusadhesion to a substrate may decrease in a die attachment process, andvoid removal during a curing process may become difficult, thus loweringreliability of the process and the final product.

If the content of the curing agent containing phenol resin is too low,it may be difficult to secure sufficient heat resistance. If the contentof the curing agent containing phenol resin is too high, even if curingis completed, non-reacted phenol groups may remain to increasehygroscopicity, and thus, in a reflow process after moisture absorptionin a semiconductor packaging process, delamination between a substrateand adhesive may be caused.

The curing agent may further include one or more kinds of compoundsselected form the group consisting of an amine-based curing agent and anacid anhydride-based curing agent. The amount of the curing agent usedmay be appropriately selected considering the properties of the finallyprepared adhesive film, and the like, and for example, it may be used inan amount of 10 to 700 parts by weight, or 30 to 300 parts by weight,based on 100 parts by weight of the epoxy resin.

The adhesive composition for a semiconductor may further include acuring catalyst.

The curing catalyst functions to facilitate the action of the curingagent or the curing of the adhesive composition for a semiconductor, andany curing catalysts known to be used in the manufacture of adhesivefilms for a semiconductor and the like may be used without significantlimitations. For example, as the curing catalyst, one or more kindsselected from the group consisting of a phosphorus compound, a boroncompound, a phosphorous-boron compound, and an imidazole-based compoundmay be used. The amount of the curing catalyst used may be appropriatelyselected considering the properties of the adhesive film, and the like,and for example, it may be used in an amount of 0.5 to 10 parts byweight, based 100 parts by weight of the liquid and solid epoxy resin,(meth)acrylate-based resin, and phenol resin.

The adhesive film for a semiconductor may further include an ionscavenger including a metal oxide including one or more metals selectedfrom the group consisting of zirconium, antimony, bismuth, magnesium,and aluminum; porous silicate; porous alumino silicate; or zeolite.

Examples of the metal oxide including one or more metals selected fromthe group consisting of zirconium, antimony, bismuth, magnesium, andaluminum may include zirconium oxide, an antimony oxide, a bismuthoxide, a magnesium oxide, an aluminum oxide, an antimony bismuth-basedoxide, a zirconium bismuth-based oxide, a zirconium magnesium-basedoxide, a magnesium aluminum-based oxide, an antimony magnesium-basedoxide, an antimony aluminum-based oxide, an antimony zirconium-basedoxide, a zirconium aluminum-based oxide, a bismuth magnesium-basedoxide, a bismuth aluminum-based oxide, or a mixture of two or more kindsthereof.

The ion scavenger may function for adsorbing metal ions or halogen ionsand the like existing inside the adhesive composition for asemiconductor or an adhesive film prepared therefrom, and thus mayimprove electrical reliability of the wires in contact with the adhesivefilm.

The content of the ion scavenger in the adhesive composition for asemiconductor is not significantly limited, but considering thereactivity with transition metal ions, workability, and the propertiesof the adhesive film manufactured from the resin composition, it may beincluded in the content of 0.01 to 20 wt %, preferably 0.01 to 10 wt %,based on the total solid weight of the adhesive composition for asemiconductor.

The adhesive composition for a semiconductor may further include 0.1 wt% to 50 wt %, or 0.1 wt % to 10 wt %, of an organic solvent. The contentof the organic solvent may be determined considering the properties ofthe adhesive composition for a semiconductor or the properties of thefinally prepared adhesive film or preparation processes thereof.

The adhesive film for a semiconductor may further include one or morekinds of additives selected from the group consisting of a couplingagent and inorganic filler. Examples of the coupling agent and inorganicfiller are not particularly limited, and components known to be usablein an adhesive for semiconductor packaging may be used withoutsignificant limitations.

According to another embodiment of the invention, provided is anadhesive film for a semiconductor including the above adhesivecomposition for a semiconductor.

The adhesive film may have a thickness of 1 μm to 300 μm. Further, theadhesive film may have a thickness of 1 μm or more, 3 μm or more, 5 μmor more, or 10 μm or more. In addition, the adhesive film may have athickness of 300 μm or less, 100 μm or less, 90 μm or less, or 70 μm orless.

The adhesive film for a semiconductor may be applied to a package of amultistage stack structure of a semiconductor chip to realize a morestable structure and excellent mechanical properties such as heatresistance, impact resistance, and the like, and prevent reflow cracksand the like, and particularly, even if exposed to a high temperaturecondition that is applied in a semiconductor manufacturing process for along time, voids may not be substantially generated.

Further, the adhesive film for a semiconductor has high breakingstrength and low elongation at break, and thus can be applied fornon-contact-type adhesive cutting, for example, DBG (Dicing BeforeGrinding), as well as wafer cutting using a knife blade, and hasexcellent cuttability even at a low temperature, and thus even if it isallowed to stand at room temperature, a possibility of readhesionbecomes low, thus increasing reliability and efficiency in asemiconductor manufacturing process.

The adhesive film for a semiconductor may include: a continuous phasebase including a thermoplastic resin having a glass transitiontemperature of −10° C. to 20° C., a curing agent containing a phenolresin having a softening point of 70° C. or more, and a liquid epoxyresin; and a solid epoxy resin dispersed in the continuous phase base.

The weight ratio of the total content of the solid epoxy resin and theliquid epoxy resin in the thermoplastic resin may be 1.6 to 2.6, or 1.7to 2.5, 1.75 to 2.4, or 1.8 to 2.3.

In the adhesive film for a semiconductor, if the weight ratio of thetotal contents of the solid epoxy resin and the liquid epoxy resin tothe thermoplastic resin is lower than the above-explained range, it mayexhibit high viscosity at a high temperature or exhibit low breakingstrength and high elongation at break, and a high temperature shearingforce may also be lowered, and thus cuttability may not be sufficientlysecured.

Further, in the adhesive film for a semiconductor, if the weight ratioof the total contents of the solid epoxy resin and the liquid epoxyresin to the thermoplastic resin is greater than 2.6, a modulusgenerated at 5% to 10% elongation of the adhesive film at roomtemperature may become significantly high, or elongation of the adhesivefilm at room temperature may be significantly lowered, thus largelyinhibiting workability. In addition, if the weight ratio of the totalcontents of the solid epoxy resin and the liquid epoxy resin to thethermoplastic resin is greater than 2.6, in the dicing die bonding filmmanufactured using the adhesive film for a semiconductor, a viscosityincrease rate may be significantly increased in the curing process, andthus it may be difficult to remove a void inside the film, which mayimpede reliability of a semiconductor package.

In the continuous phase base included in the adhesive film for asemiconductor, the weight ratio of the phenol resin to the total weightof the thermoplastic resin, the phenol resin, and the liquid epoxy resinmay be 0.280 or more, 0.300 or more, or 0.300 to 0.600.

If the weight ratio of the phenol resin to the total weight of thethermoplastic resin, the phenol resin, and the liquid epoxy resin isless than 0.280 in the adhesive film for a semiconductor, a modulusgenerated at 5% to 10% elongation of the adhesive film at roomtemperature may be significantly lowered, and yet elongation of theadhesive film at room temperature may be significantly increased.Further, in a dicing die bonding film manufactured using the adhesivefilm, burrs may be excessively generated through a dicing process, andhigh temperature shearing force may also be decreased, and thuscuttability may not be sufficiently secured.

The adhesive film for a semiconductor may be a die bonding film. Thus,the adhesive film for a semiconductor may include: an adhesive layerincluding a continuous phase base including thermoplastic resin having aglass transition temperature of −10° C. to 20° C., a curing agentcontaining a phenol resin having a softening point of 70° C. or more,and a liquid epoxy resin; and a solid epoxy resin dispersed in thecontinuous phase base and a release film formed on one side of theadhesive layer.

A modulus generated at 5% to 10% elongation of the adhesive film for asemiconductor at room temperature may be 50 MPa or more. Since themodulus generated at 5% to 10% elongation of the adhesive film for asemiconductor at room temperature is 50 MPa or more, or 50 MPa to 300MPa, the adhesive film of the above embodiment may be easily applied fornon-contact-type cutting methods, for example, DBG (Dicing BeforeGrinding), as well as a wafer cutting method using a knife blade, andthus has excellent cuttability even at a low temperature.

If a modulus generated at 5% to 10% elongation of the adhesive film fora semiconductor at room temperature is less than 50 MPa, even ifexpanding is conducted at a low temperature, cuttability may not besufficient; if allowed to stand at room temperature, readhesion mayoccur; and due to the heat generated when cutting a wafer to which theadhesive film is bonded, an adhesive may be softened to generate burrsin the adhesive film, thus contaminating the circuit side of asemiconductor chip.

Moreover, the adhesive film for a semiconductor may have elongation of500% or less, 50 to 500%, or 100 to 400% at room temperature. Since theadhesive film for a semiconductor has relatively high elasticity and yetexhibits low elongation and low elongation at break, it may haveexcellent cuttability even at a low temperature, and may secureexcellent cuttability even when non-contact-type cutting methods, forexample, DBG (Dicing Before Grinding), are applied, as well as a wafercutting method using a knife blade.

Meanwhile, if the adhesive film for a semiconductor exhibits elongationgreater than 500%, even if expanding is conducted at a low temperature,cuttability may not be sufficient; if allowed to stand at roomtemperature, readhesion may occur; and due to the heat generated whencutting a wafer to which the adhesive film is bonded, an adhesive may besoftened to generate burrs in the adhesive film, thus contaminating thecircuit side of a semiconductor chip.

Further, the adhesive film for a semiconductor has a melt viscosity of1,000 Pa·s to 4,000 Pa·s at a temperature of 110° C. and a shear rate of5 rad/s. As the adhesive film has relatively low viscosity at atemperature of about 110° C., it may have excellent adhesive strengthand flow properties that are optimized for a semiconductor, it may befavorable for void removal at the interface of the initial stage curingand in a die attachment process, and after die attachment, penetrationof a bonding wire into a surrounding space may be smoothly achievedwithout significantly influencing the shape or properties of theadhesive film.

Further, as the adhesive film for a semiconductor has a melt viscosityof 1,000 Pa·s to 4,000 Pa·s at a temperature of 110° C. and a shear rateof 5 rad/s, even if exposed to a high temperature condition that isapplied in a semiconductor manufacturing process for a long time, a voidmay not be substantially generated, and when applied for a dicing diebonding film and the like, sufficient high temperature shearing forcemay be secured, thus securing excellent cuttability.

The adhesive film may be used as a die attach attachment film (DAF) forattaching a lead frame or a substrate with a die or attaching a die witha die. Thus, the adhesive film may be processed in the form of a diebonding film, a dicing die bonding film, and the like.

The die bonding film may further include an inorganic filler dispersedin the continuous phase base.

The details of the adhesive composition for a semiconductor of theembodiment include above-explained particulars.

Meanwhile, according to yet another embodiment of the invention,provided is a dicing die bonding film including a base film; a tackylayer formed on the base film; and an adhesive layer formed on the tackylayer, and including the above-explained adhesive composition for asemiconductor.

As the adhesive layer includes the adhesive composition for asemiconductor of the above-explained embodiment, the dicing die bondingfilm may have excellent mechanical properties such as heat resistance,impact resistance, and the like, high adhesive strength, and lowhygroscopicity, thus preventing vaporization of moisture, delaminationbetween a substrate and a die bonding film, or reflow cracks due to thevaporization and the like.

The details of the adhesive composition for a semiconductor are asexplained above.

A modulus generated at 5% to 10% elongation of the adhesive film for asemiconductor at room temperature may be 50 MPa or more.

Further, elongation of the adhesive film for a semiconductor at roomtemperature may be 500% or less.

In addition, the adhesive film for a semiconductor may have a meltviscosity of 1,000 Pa·s to 4,000 Pa·s at a temperature of 110° C. and ashear rate of 5 rad/s.

The kind of the base film included in the dicing die bonding film is notspecifically limited, and for example, plastic films or metal foils andthe like known in this field may used.

For example, the base film may include low density polyethylene, linearpolyethylene, medium density polyethylene, high density polyethylene,ultra-low density polyethylene, a random copolymer of polypropylene, ablock copolymer of polypropylene, a homopolypropylene, apolymethylpentene, an ethylene-vinylacetate copolymer, anethylene-methacrylic acid copolymer, an ethylene-methylmethacrylatecopolymer, an ethylene-ionomer copolymer, an ethylene-vinylalcoholcopolymer, a polybutene, a copolymer of styrene, or a mixture of two ormore kinds thereof.

The base film including a mixture of two or more kinds of polymersincludes both a multi-layered film wherein each film layer includes theabove-explained polymer, and a mono-layered film including two or morekinds of the above-explained polymers.

The thickness of the base film is not specifically limited, andcommonly, it is formed to a thickness of 10 μm to 200 μm, and preferably50 μm to 180 μm. If the thickness is less than 10 μm, there is a concernthat the control of cut depth may be unstable in a dicing process, andif it is greater than 200 μm, a lot of burrs may be generated in adicing process, or elongation may decrease, and thus an expandingprocess may not be precisely achieved.

The base film, if necessary, may be subjected to general physical orchemical treatments such as a matte treatment, corona discharge, aprimer treatment, crosslinking, and the like.

Meanwhile, the tacky layer may include a UV curable adhesive or a heatcurable adhesive. In case the UV curable adhesive is used, UV isirradiated from the base film side to increase cohesiveness and glasstransition temperature of the adhesive, thus lowering adhesive strength,and in case the heat curable adhesive is used, the temperature isincreased to lower adhesive strength.

Moreover, the UV curable adhesive may include a (meth)acrylate-basedresin, a UV curable compound, a photoinitiator, and a crosslinkingagent.

The (meth)acrylate-based resin may have a weight average molecularweight of 100,000 to 1,500,000, preferably 200,000 to 1,000,000. If theweight average molecular weight is less than 100,000, coatability orcohesiveness may be lowered, and thus a residue may remain in theadherent at the time of delamination, or adhesive destruction may occur.Further, if the weight average molecular weight is greater than1,500,000, the base resin may hinder the reaction of the UV curablecompound, and thus there is a concern that a decrease in peel strengthmay not be efficiently achieved.

Examples of the (meth)acrylate-based resin may include a copolymer of(meth)acrylic acid ester-based monomers and crosslinkable functionalgroup-containing monomers. Herein, examples of the (meth)acrylic acidester-based monomers may include alkyl (meth)acrylate, specificallymonomers having an alkyl group having a carbon number of 1 to 12, suchas pentyl (meth)acrylate, n-butyl (meth)acrylate, ethyl(meth)acrylate,methyl (meth)acrylate, hexyl (meth)acrylate, n-octyl (meth)acrylate,isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, dodecyl(meth)acrylate, decyl (meth)acrylate, or a mixture thereof. As thecarbon number of the alkyl of the monomer becomes higher, the glasstransition temperature of the final copolymer becomes lower, and thusappropriate monomers may be selected according to the desired glasstransition temperature.

Examples of the crosslinkable functional group-containing monomers mayinclude hydroxyl group-containing monomers, carboxyl group-containingmonomers, nitrogen-containing monomers, or mixtures thereof. Examples ofthe hydroxyl group-containing compounds may include 2-hydroxyethyl(meth)acrylate, 2-hydroxypropyl (meth)acrylate, and the like, examplesof the carboxyl group-containing compounds may include (meth)acrylateand the like, and examples of the nitrogen-containing monomers mayinclude (meth)acrylonitrile, N-vinyl pyrrolidone, N-vinyl caprolactam,and the like, but are not limited thereto.

In the (meth)acrylate-based resin, carbon-carbon double bond-containinglow molecular weight compounds such as vinyl acetate, styrene,acrylonitrile, and the like may be additionally included so as toimprove other functionalities such as compatibility and the like.

The kind of the UV curable compounds is not specifically limited, andfor example, multifunctional compounds having a weight average molecularweight of 500 to 300,000 (e.g. multifunctional urethane acrylate,multifunctional acrylate monomers or oligomers, and the like) may beused. One of ordinary knowledge in the art could easily selectappropriate compounds according to the desired use.

The content of the UV curable compound may be 5 to 400 parts by weight,preferably 10 to 200 parts by weight, based on 100 parts by weight ofthe above-explained base resin. If the content of the UV curablecompound is less than 5 parts by weight, an adhesion decrease aftercuring may not be sufficient, and thus, there is a concern of loweringpick-up, and if it is greater than 400 parts by weight, cohesiveness ofthe adhesive before UV irradiation may be insufficient, or delaminationfrom a release film and the like may not be easily achieved.

The kind of the photoinitiator is not specifically limited, and thosecommonly known in this field may be used, wherein the content may be0.05 parts by weight to 20 parts by weight, based on 100 parts by weightof the UV curable compound. If the content of the photoinitiator is lessthan 0.05 parts by weight, a curing reaction by UV irradiation maybecome insufficient to lower pick-up, and if it is greater than 20 partsby weight, a crosslinking reaction may occur with a short unit in thecuring process, non-reacted UV curable compounds may be generated tocause residue on the adherent surface, or peel strength after curing mayexcessively decrease to lower pick-up.

Further, the kind of the crosslinking agent that is included in theadhesive part to afford adhesion and cohesiveness is also notspecifically limited, and those commonly used such as isocyanate-basedcompounds, aziridine-based compounds, epoxy-based compounds, metalchelate-based compounds, and the like may be used. The crosslinkingagent may be included in the content of 2 parts by weight to 40 parts byweight, preferably 2 parts by weight to 20 parts by weight, based on 100parts by weight of the base resin. If the content is less than 2 partsby weight, cohesiveness of the adhesive may be insufficient, and if itis greater than 20 parts by weight, adhesion before UV irradiation maybe insufficient, and thus there is a concern of chip scattering and thelike.

Further, in the tacky layer, tackifiers such as a rosin resin, a terpeneresin, a phenol resin, a styrene resin, an aliphatic petroleum resin, anaromatic petroleum resin, an aliphatic aromatic copolymer petroleumresin, and the like may be further included.

A method for forming a tacky layer including the above components on abase film is not specifically limited, and for example, a method ofdirectly coating an adhesive composition on a base film to form a tackylayer, or a method of firstly coating an adhesive composition on apeelable base to prepare a tacky layer, and then transcribing the tackylayer to a base film using a peelable base, and the like may be used.

Herein, the methods of coating and drying an adhesive composition arenot specifically limited, and for example, a method of coating thecomposition including the above components as it is, or diluting it inan appropriate organic solvent and coating by known means such as acomma coater, a gravure coater, a die coater, a reverse coater, and thelike, and then drying the solvent at a temperature of 60° C. to 200° C.for 10 s to 30 min may be used. Further, in the above process, an agingprocess may be further conducted so as to progress sufficientcrosslinking of the adhesive.

Although the thickness of the tacky layer is not significantly limited,for example, it may be in the range of 1 μm to 600 μm, 3 μm to 500 μm,or 5 μm to 300 μm.

As explained above, the adhesive layer is formed on the tacky layer, andmay include the adhesive film for a semiconductor of the above-explainedembodiment. The details of the adhesive film for a semiconductor includethose explained above.

Although the thickness of the adhesive layer is not significantlylimited, for example, it may be 1 μm to 300 μm. Further, the adhesivefilm may have a thickness of 1 μm or more, 3 μm or more, 5 μm or more,or 10 μm or more. In addition, the adhesive film may have a thickness of300 μm or less, 100 μm or less, 90 μm or less, or 70 μm or less.

The dicing die bonding film may further include a release film formed onthe adhesive layer. Examples of the release film that can be used mayinclude one or more kinds of plastic films such as a polyethyleneterephthalate film, a polytetrafluoroethylene film, a polyethylene film,a polypropylene film, a polybutene film, a polybutadiene film, avinylchloride copolymer film, a polyimide film, and the like.

The surface of the release film may be treated with one or more ofalkyd-based, silicon-based, fluorine-based, unsaturated ester-based,polyolefin-based, or wax-based release agents, among which heatresistant alkyd-based, silicon-based, or fluorine-based release agentsmay be preferable.

The release film may be commonly formed to a thickness of 10 μm to 500μm, preferably about 20 μm to 200 μm, but is not limited thereto.

A method for manufacturing the above-explained dicing die bonding filmis not specifically limited, and for example, a method of sequentiallyforming a tacky part, an adhesive part, and a release film on a basefilm, or a method of separately preparing a dicing film (a base film+atacky part) and a release film on which a die bonding film or anadhesive part is formed, and then laminating them, and the like, may beused.

The lamination method is not specifically limited, and hot rolllamination or a laminate press may be used, among which hot rolllamination is preferable in terms of possibility of a continuous processand efficiency. The hot roll laminate may be conducted at a temperatureof 10° C. to 100° C. and a pressure of 0.1 kgf/cm² to 10 kgf/cd, but isnot limited thereto.

According to yet another embodiment of the invention, provided is amethod for dicing a semiconductor wafer, including the steps of:partially pre-treating a semiconductor wafer including the dicing diebonding film; laminating a wafer on at least one side of the dicing diebonding film so as to be completely cut or cuttable; and irradiating UVto the base film of the pre-treated semiconductor wafer, and picking upindividual chips separated by the cutting of the semiconductor.

The details of the dicing die bonding film include those explainedabove.

Except the particulars regarding the steps of the dicing method,commonly known apparatuses and methods used for the dicing method of asemiconductor wafer and the like may be used without specificlimitations.

The method for dicing a semiconductor wafer may further include a stepof expanding the semiconductor wafer after the pretreatment. In thiscase, processes of irradiating UV to the base film of the expandedsemiconductor wafer and picking up individual chips separated by cuttingof the semiconductor wafer are followed.

By using the dicing die bonding film including the dicing film, burrsthat may be generated during a dicing process of a semiconductor wafermay be minimized, thus preventing contamination of a semiconductor chipand improving reliability and lifetime of a semiconductor chip.

Specific embodiments of the invention will be explained in detail in thefollowing examples. However, these examples are only to illustratespecific embodiments of the invention, and the scope of the invention isnot limited thereto.

Examples 1 to 5 and Comparative Examples 1 to 3: Preparation of anAdhesive Composition for a Semiconductor and an Adhesive Film for aSemiconductor Example 1

(1) Preparation of a Solution of an Adhesive Composition for aSemiconductor

40 g of phenol resin KH-6021 (produced by DIC Corporation, bisphenol Anovolac resin, hydroxyl equivalent weight 121 g/eq, softening point:125° C.), which is a curing agent of epoxy resin, 38 g of epoxy resinEOCN-1045 (produced by Nippon Kayaku Co., Ltd., cresol novolac type ofepoxy resin, epoxy equivalent weight 214 g/eq, softening point: 83° C.),50 g of liquid epoxy resin RE-310S (produced by Nippon Kayaku Co., Ltd.,bisphenol A epoxy resin, epoxy equivalent weight 180 g/eq), 40 g ofthermoplastic acrylate resin KG-3015 (Mw: 900,000, glass transitiontemperature: 10° C.), 5 g of silane coupling agent A-187 (GE ToshibaSilicone, gamma-glycidoxypropyltrimethoxysilane), 0.1 g of a curingaccelerator 2PZ (Shikoku Chemicals Corporation, 2-phenyl imidazole), and100 g of filler SC-2050 (Admatec Corporation, spherical silica, meanparticle diameter about 400 nm) were mixed in a methyl ethyl ketonesolvent to obtain a solution of an adhesive composition for asemiconductor (solid content 20 wt %).

(2) Preparation of a Die Bonding Film

The above prepared solution of an adhesive composition for asemiconductor was coated on a release-treated polyethylene terephthalatefilm (thickness 38 μm), and then dried at 110° C. for 3 min to obtain anadhesive film for a semiconductor (die bonding film) with a thickness ofabout 60 μm.

Examples 2 to 5

Solutions of adhesive compositions for a semiconductor (solid content 20wt %) and adhesive films for a semiconductor (die bonding films) wereobtained by the same method as Example 1, except for applying thecomponents and the amounts described in the following Table 1.

Comparative Examples 1 and 2

Adhesive films for a semiconductor (die bonding films) were obtained bythe same method as Example 1, except that solutions of adhesivecompositions for a semiconductor (methyl ethyl ketone 20 wt %concentration) were prepared using the components and the contents ofthe following Table 1.

TABLE 1 Compositions of the resin compositions of examples andcomparative examples [unit: g] Comparative Comparative Example 1 Example2 Example 3 Example 4 Example 5 Example 6 Example 1 Example 2 Phenol KH-40 59 59 60 40 resin 6021 GPH- 60 40 103 HE200C- 20 17 KPH- 40 3065Liquid RE- 50 50 40 40 35 40 65 50 epoxy 310S resin solid epoxy EOCN- 3835 35 32 45 45 35 45 resin 104S acryl resin KG- 40 40 40 40 40 40 40 403015P Curing 2PZ 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 accelerator CouplingA-187 5 5 5 5 5 5 5 5 agent Filler SC- 100 100 100 100 110 110 100 1002050 KH-6021: bisphenol A novolac resin (DIC Corporation, softeningpoint: 125° C.) GPH-103: biphenyl novolac resin (Nippon Kayaku Co.,Ltd., softening point: 103° C.) HE200C-17: biphenyl novolac resin (AirWater Co., Ltd., softening point: 75° C.) KPH-3065: xyloc A novolacphenol resin (Kolon Chemical Co., Ltd., hydroxyl equivalent weight: 180g/eq, softening point 67° C.) KG-3015P: acrylate-based resin (including3 wt % of glycidylmethacrylate-based repeat units, glass transitiontemperature: 10° C., weight average molecular weight 900,000) EOCN-104S:cresol novolac epoxy (Nippon Kayaku Co., Ltd., epoxy equivalent weight:180 g/eq, softening point: 90° C.) RE-310S: bisphenol A epoxy liquidresin (Nippon KayaKu, epoxy equivalent weight: about 180 g/eq, viscosityat 25° C.: about 13,000 to 17,000 mPa · s)

EXPERIMENTAL EXAMPLES: ASSESSMENT OF THE PROPERTIES OF ADHESIVE FILMSFOR A SEMICONDUCTOR Experimental Example 1: Measurement of MeltViscosity

The adhesive films respectively obtained in examples and comparativeexamples were stacked to a thickness of 650 μm, and then laminated usinga roll laminator at 60° C. Thereafter, each specimen was formed in acircular shape with a diameter of 10 mm, and then melt viscosityaccording to temperature was measured at a temperature range of 40° C.to 160° C., a shear rate of 1 Hz and 5 rads, and a temperature rise rateof 20° C./min, using advanced rheometric expansion system (ARES) of TACorporation.

Experimental Example 2: Assessment of Room Temperature TensileProperties

In order to measure the tensile properties of the adhesive filmsrespectively obtained in examples and comparative examples, a TextureAnalyzer (Stable Micro System, Ltd.) was used. Specifically, theadhesive films respectively obtained in examples and comparativeexamples were cut to a size of width 15 mm and length 100 mm to preparesamples, and both ends were taped while leaving 50 mm of the centralpart of the sample. Further, both ends of the taped samples were fixedto the apparatus, and while elongating at a speed of 0.3 mm/s, a tensilecurve was drawn. From the tensile curve, a gradient value at 5%elongation was measured to determine a modulus, and a time when thesample was completely cut was measured to determine elongation.

Experimental Example 3: Observation of Burr Generation

(1) Manufacture of a Dicing Film

75 g of 2-ethylhexyl acrylate, 10 g of 2-ethylhexyl methacrylate, and 15g of 2-hydroxyethyl acrylate were copolymerized in 300 g of anethylacrylate solvent to obtain a copolymer having a weight averagemolecular weight of 850,000 (glass transition temperature: 10° C.), andthen 10 g of a photocurable material acrylisocyanate compound was addedthereto, thus obtaining a reactant. Thereafter, 10 g of amultifunctional isocyanate oligomer and 1 g of Darocur TPO as aphotoinitiator were mixed to prepare a UV curable adhesive composition.

The UV curable adhesive composition was coated on a release-treatedpolyester film having a thickness of 38 μm so that the thickness afterdrying became 10 μm, and dried at 110° C. for 3 min. The dried tackylayer was laminated on a polyolefin film having a thickness of 100 μm tomanufacture a dicing film.

(2) Manufacture of a Dicing Die Bonding Film

The tacky layer obtained in the above process and each adhesive filmobtained in examples and comparative examples (width: 18 mm, length: 10cm) were laminated to manufacture a multi-layered adhesive film fordicing die bonding.

(3) Measurement of Burr Generation Rate

Each dicing die bonding film prepared above was laminated at 50° C.using a 100 μm wafer and a wafer ring mounter, and diced to a 10 mm*10mm chip size at a speed of 40K rpm and 20 mm/s, using a dicingapparatus, and then the number of burrs generated on the die wasconfirmed to measure the burr generation rate.

Experimental Example 4: Assessment of High Temperature Shearing Force

On the mirror side of a wafer having a thickness of about 600 μm to 700μm, the adhesive films respectively obtained in examples and comparativeexamples were laminated under a condition of 60° C., and the wafer wasfragmented to a size of 5 mm*5 mm to prepare adhesive films with the diesize. Further, a 70 μm wafer mirror of a 10 mm*10 mm size was located ona hot plate at 130° C., and then the die bonding film was attached underconditions of a wafer die at 2 kg and 2 s, curing was progressed at 125°C. for 1 h, and curing was progressed again at 175° C. for 2 h.

In addition, using a Die Shear Tester DAGE 4000, while pushing the waferdie at 250° C. at a speed of 0.05 mm/s, force was measured, to measurethe high temperature shearing force.

Experimental Examples 5: Assessment of Cuttability

The adhesives obtained in Examples 1 to 4 and Comparative Examples 1 and2 were laminated to dicing films, thus manufacturing dicing die bondingfilms.

Using an 8 inch wafer with a 50 μm thickness that was pre-cut to a sizeof 5 mm*5 mm and a wafer ring mounter, each dicing die bonding filmprepared above was laminated at 60° C., and then allowed to stand atroom temperature for 30 min. Thereafter, the wafer to which the dicingdie bonding film was laminated was installed in a low temperaturechamber, and low temperature expansion was conducted to a height of 5 mmat a speed of 100 mm/s at −10° C. Further, the wafer was transferred toa thermal shrinking device, and expanded to 4 mm at 1 mm/s, and thenheated to thermally shrink the dicing film. Thereafter, the cut ratio ofthe wafer at room temperature was confirmed.

TABLE 2 Results of Experimental Examples Comparative Comparative Example1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 1 Example 2Melt viscosity 2000 1900 2100 1900 2000 1970 2600 2200 (5 rads, 110° C.)[unit: Pa * s] Modulus at 5% 66 84 110 130 110 95 38 25 elongation atroom temperature [unit: MPa] Modulus at 10% 59 75 95 115 97 89 32 21elongation at room temperature [unit: MPa] Room 350 290 250 150 210 250550 750 temperature elongation [unit: %] High temperature 7.8 8.1 10.211.2 6.5 6.7 5.6 3.2 shearing force [unit: Mpa] Whether or not Not NotNot Not Not Not 20% 35% burr is generated generated generated generatedgenerated generated generated generated generated Cuttability 100% 100%100% 100% 100% 100% 70% 50%

As shown in the Table 2, the adhesive films of Examples 1 to 5 wereprepared such that the weight ratio of the total contents of the solidepoxy resin and liquid epoxy resin to the thermoplastic resin became 1.6to 2.6, and these adhesive films have physical properties of a modulusgenerated at 5% to 10% elongation at room temperature of 50 MPa to 150MPa, melt viscosity of 1,000 Pa·s to 4,000 Pa·s at a temperature of 110°C. and a shear rate of 5 rad/s, and elongation at room temperature of500% or less. It was confirmed that as the adhesive films of theexamples have the above-explained physical properties, even if anexpanding process is conducted at a low temperature, 100% cuttabilitymay be secured.

It was also confirmed that in the dicing die bonding films manufacturedusing the adhesive films of Examples 1 to 5, burrs are not substantiallygenerated through the dicing process, and the adhesive films of Examples1 to 5 have high high-temperature shearing force and thus have improvedheat resistance and adhesive strength.

The adhesive film of Comparative Example 1 was prepared such that theweight ratio of the total contents of the solid epoxy resin and theliquid epoxy resin to the thermoplastic resin became greater than 2.6,and the weight ratio of the phenol resin to the total weight of thethermoplastic resin, phenol resin, and liquid epoxy resin became lessthan 0.280. As shown in Table 2, it was confirmed that in the case ofthe adhesive film of Comparative Example 1, a modulus generated at 5% to10% elongation at room temperature is less than 40 MPa, and elongationat room temperature is greater than 550%.

It was also confirmed that in the case of Comparative Example 2 whereina phenol resin having a low softening point was used, a modulusgenerated at 5% to 10% elongation at room temperature is less than 30MPa, and elongation at room temperature amounts to 750%. It wasconfirmed that as the adhesive films of Comparative Examples 1 and 2have high elongation at room temperature, and they have low cuttabilityin the low temperature expanding process, and thus it is difficult tosecure sufficient cuttability, as shown in the Table 2.

Further, it was confirmed that in the dicing die bonding filmsmanufactured using the adhesive films of Comparative Examples 1 and 2,burrs are generated at 20% or more through the dicing process, and thatthe adhesive films of Comparative Examples 1 and 2 do not havesufficient high temperature shearing force, and thus it is difficult tosecure sufficient adhesive strength.

1. An adhesive composition for a semiconductor comprising: athermoplastic resin having a glass transition temperature of −10° C. to20° C.; a curing agent containing a phenol resin having a softeningpoint of 70° C. or more; a solid epoxy resin; and a liquid epoxy resin,wherein a weight ratio of total contents of the solid epoxy resin andthe liquid epoxy resin to the thermoplastic resin is 1.6 to 2.6.
 2. Theadhesive composition according to claim 1, wherein a weight ratio oftotal contents of the solid epoxy resin and the liquid epoxy resin tothe thermoplastic resin is 1.7 to 2.5.
 3. The adhesive compositionaccording to claim 1, wherein a weight ratio of the phenol resin to thetotal weight of the thermoplastic resin, the phenol resin, and theliquid epoxy resin is 0.280 or more.
 4. The adhesive compositionaccording to claim 1, wherein a weight ratio of the phenol resin to thetotal weight of the thermoplastic resin, the phenol resin, and theliquid epoxy resin is 0.300 to 0.600.
 5. The adhesive compositionaccording to claim 1, wherein the liquid epoxy resin has a viscosity of500 mPa·s to 20,000 mPa·s at 25° C.
 6. The adhesive compositionaccording to claim 1, wherein the liquid epoxy resin has an epoxyequivalent weight of 100 to 1,000.
 7. The adhesive composition accordingto claim 1, wherein the phenol resin has a hydroxyl equivalent weight of100 g/eq to 178 g/eq.
 8. The adhesive composition according to claim 1,wherein the phenol resin has a softening point of greater than 100° C.and 160° C. or less.
 9. The adhesive composition according to claim 1,wherein the thermoplastic resin includes one or more polymer resinsselected from the group consisting of polyimide, polyether imide,polyester imide, polyamide, polyether sulfone, polyether ketone,polyolefin, polyvinylchloride, phenoxy, reactive butadiene acrylonitrilecopolymer rubber, and (meth)acrylate-based resin.
 10. The adhesivecomposition according to claim 9, wherein the (meth)acrylate-based resinis a (meth)acrylate-based resin comprising (meth)acrylate-based repeatunits including an epoxy-based functional group, and having a glasstransition temperature of −10° C. to 20° C.
 11. The adhesive compositionaccording to claim 10, wherein the (meth)acrylate-based resin comprises0.1 wt % to 10 wt % of (meth)acrylate-based repeat units including anepoxy-based functional group.
 12. The adhesive composition according toclaim 1, further comprising an ion scavenger including a metal oxideincluding one or more metals selected from the group consisting ofzirconium, antimony, bismuth, magnesium, and aluminum; porous silicate;porous alumino silicate; or zeolite.
 13. An adhesive film for asemiconductor comprising the adhesive composition for a semiconductor ofclaim
 1. 14. The adhesive film according to claim 13, wherein theadhesive film has a thickness of 1 μm to 300 μm.
 15. A dicing diebonding film comprising a base film; a tacky layer formed on the basefilm; and an adhesive layer comprising the adhesive composition for asemiconductor of claim 1, formed on the tacky layer.
 16. The dicing diebonding film according to claim 15, wherein the base film has athickness of 10 μm to 200 μm, the tacky layer has a thickness of 1 μm to600 μm, and the adhesive film has a thickness of 1 μm to 300 μm.